1. Field of the Invention
The present invention relates to a showcase structure on which goods or articles such as foods or drinks packed in cans or bottles, i.e., canned foods or drinks and bottled drinks, etc. are placed for sale in shops, such as supermarkets, drugstores, convenience stores and the like. Usually, such a showcase structure comprises a roller support frame that is arranged so as to have a down-slope from the rear end toward the front end of the roller support frame, and on which a plurality of parallel sets of rollers are mounted. The rollers in each parallel set of rollers are mounted rotatably on the roller support frame and arranged one after another from the rear end toward the front end of the roller support frame. Individual articles, such as canned drinks, may be placed across two or more parallel sets of the rollers so that the articles can be moved or slid down one by one along those rollers from the rear end toward the front end.
More specifically, the present invention relates to a showcase assembly unit for such a showcase structure.
2. Prior Art
FIG. 7 represents a showcase structure that is installed in shops such as supermarkets, drugstores, convenience stores and the like, and FIG. 8 shows a conventional showcase assembly unit that is designed for use with the showcase structure shown in FIG. 7.
As shown in FIG. 8, the showcase assembly unit includes a roller support frame 1 that is arranged so as to have a down-slope from the rear end toward the front end, and on which a plurality of parallel sets of rollers A, B, etc. are mounted across the roller support frame 1. The rollers in each set A, B are rotatably mounted and arranged one after another from the rear end toward the front end. And the rollers in each set A, B are arranged in parallel with the rollers in each adjacent set across the roller support frame. For example, as shown in FIG. 8 and FIG. 10, set A includes a plurality of rollers 2a, 2b, etc. arranged one after another from the rear end toward the front end of the roller support frame 1, and set B includes a plurality of rollers 12a, 12b, etc. arranged similarly and in parallel with the set of rollers A across the roller support frame 1.
The rollers in each set A, B, such as the roller 2a, etc. are each mounted rotatably in the respective directions indicated by arrows 41 or 42 in FIG. 9 so as to permit the articles thereon to roll or slide down one by one toward the front end.
Then, when a consumer picks up an article that is shown at the foremost end 45, as shown by an arrow 46 in FIG. 8, from the articles placed in series on a particular set of rollers, such as the sets A and B in this case, in the showcase structure in FIG. 7, the articles 47 that follow the article 45 just picked up will automatically move down toward the front end one by one along the rollers as shown by arrow 48 in FIG. 8.
It may be seen from FIG. 10 that the conventional showcase assembly unit for the showcase structure includes several parallel sets of rollers A, B, C, D that are mounted across the showcase assembly unit, in which the respective rollers in any two adjacent sets are axially aligned with each other. For example, each of the rollers 2a, 2b, 2c, etc. in set A is axially aligned with a corresponding one of the rollers 12a, 12b, 12c, etc. in set B.
FIG. 9 represents the conventional showcase assembly unit for the showcase structure shown in FIGS. 8 and 10, which shows the sequence of rollers as viewed from the side to explain how a particular article, such as a canned drink, moves (slides) on the rollers. FIG. 9 also shows, on an enlarged scale, how the bottom of the article makes contact with the top of the sequence of the rollers.
It may be noticed, as shown in FIG. 10 that each of the rollers in set A is axially aligned with a corresponding one of the rollers in set B, which is parallel to set A. For example, roller 2a in set A is axially aligned with its corresponding roller 12a in set B. Similarly, roller 2b in set A is axially aligned with its corresponding roller 12b in set B.
As viewed from the side of the roller sequence as shown in FIG. 9, roller 12a in set B is hidden behind roller 2a in set A, and roller 12b is hidden behind roller 2b in set A.
As shown in FIG. 9, there is a large gap S that is created on the top between adjacent rollers 2a and 2b in set A, as well as between adjacent rollers 12a and 12b in set B, which are not seen behind rollers 2a and 2b. 
Thus, when an article 5, such as a canned drink, is moving along the rollers in the parallel sets A and B as shown in FIG. 10, the article must overcome the large gap S on the top between the rollers 2a and 2b, between the rollers 12a and 12b, between the rollers 2b and 2c, and between the rollers 12b and 12c, etc.
This gap S (FIG. 9) may have a different size, depending on the diameters of the adjacent rollers, for example, rollers 2a and 2b and rollers 12a and 12b, and also depending on the interval between the outer surfaces of the adjacent rollers, for example, between the outer surfaces of rollers 2a and 2b, etc.
In any case, as each of the rollers 2a, 2b, 2c, etc. in set A is axially aligned with a corresponding one of the rollers 12a, 12b, 12c, etc. in set B as shown in FIG. 10, the gap S on the top between the respective adjacent rollers in the parallel sets of rollers, for example, rollers 2a and 2b in set A and rollers 12a and 12b in set B, must be large as viewed from the side in FIG. 9.
When an article 5 is moving down along the rollers, as indicated by an arrow 48 in FIG. 8, it may cause a jolting motion, thereby producing a large noise and much friction each time it moves past the gap S between the adjacent rollers.
When the article 5 is moving from the position shown by phantom lines 5a to the position shown by phantom lines 5b in FIG. 9, it cannot be maintained at a constant level or height, because the large gap S exists between adjacent rollers 2a and 2b in set A as well as between adjacent rollers 12a and 12b in set B (not seen), as viewed from the side in FIG. 9. Thus, each time the article 5 moves past the large gap S, it may cause a jolting motion and produce a large noise. It may be seen in FIG. 9 that the article is higher when it is placed in the position 5b than when it is placed in the position 5a. 
It may be understood from the forgoing description that when a number of individual articles, that are placed one after another on the rollers from the rear end toward the front end of the roller support frame, are moving down one by one, as shown by arrow 48 in FIG. 8, the individual articles may receive a force that prevents them from moving forward, depending on the particular shape of the bottom of the article and the particular physical size of the article.
This problem may be solved by two possible ways. One way is to incline the roller support frame more greatly so that the articles can overcome the force that resists their movement. The other way is to make the outer diameter of each individual roller as small as possible and to make the interval between the outer surfaces of adjacent rollers as small as possible so that the gap S which is created on the top between the adjacent rollers 2a and 2b, for example, can be smaller.
In the former case, however, the articles may be moving forwardly rapidly. Thus, some adequate means must be provided for preventing any one of the following articles 47 from jumping out. Otherwise, the articles 47 that follow the foremost article 45 may exert a great force against the article 45, which makes it difficult for a consumer to pick up the article 45. For the latter case, additional manufacturing costs would be incurred, and easy maintenance would be impossible.
An object of the present invention is to solve the problems associated with the conventional showcase assembly unit for the showcase structure as described above, and therefore to propose to provide a showcase assembly unit for the showcase structure in which individual commercial articles represented by foods or drinks packed in cans or bottles, i.e., canned foods or drinks, may be placed one after another along and across the rollers so that when those articles are moved from the rear end toward the front end one by one, each article can be moved with stability while it is maintained at a constant height, without causing a jolting motion or producing a large noise, and with less frictional force.
In order to attain the above object, the showcase assembly unit for the showcase structure proposed by the present invention may comprise the following elements.
Generally, the showcase assembly unit includes a roller support frame, and a plurality of parallel sets of rollers mounted on the roller support frame. The rollers in each set are rotatably mounted on the roller support frame and arranged one after another from the rear end toward the front end of the roller support frame.
More specifically, a first set of rollers is mounted on the roller support frame. The rollers in this first set of rollers are rotatably mounted on the roller support frame and arranged one after another from the rear end toward the front end of the roller support frame. A second set of rollers is mounted on the roller support frame in parallel with and adjacent to the first set of rollers. The rollers in this second set of rollers are rotatably mounted on the roller support frame and arranged one after another from the rear end toward front end of the roller support frame. Other sets of rollers are also mounted in the same manner as that for the first and second sets of rollers. Individual articles, such as foods or drinks packed in cans or bottles, i.e., canned foods or drinks, and bottled drinks, etc., may be placed across the adjacent sets of rollers so that the individual articles can move down one by one along the rollers toward the front end of the roller support frame.
Each of the rollers in each of the plurality of parallel sets of rollers has a predetermined width that is smaller than a dimension of the bottom of a particular individual article that extends across each of the rollers, so as to permit the individual articles to be placed across two or more rollers in the sets that are adjacent to each other. And, each of the rollers in each of adjacent parallel sets of rollers is axially offset relative to a corresponding one of the rollers in the other of the adjacent parallel sets, in the direction from the rear end toward the front end of the roller support frame.
A single article, such as a canned drink or bottled drink, may be placed across two or more adjacent parallel sets of rollers as each roller is less wide than the dimension of the bottom of the article that extends across the rollers, and is capable of moving across and along these rollers toward the front end of the roller support frame.
More specifically, for sets of rollers A and B which are adjacent to each other, for example, each of rollers 2a, 2b, 2c, etc. in set A is axially offset relative to a corresponding one of rollers 12a, 12b, 12c, etc. in set B.
When those sets of rollers A and B are viewed from the side, the rollers 12a, 12b, 12c, etc. in set B are visible although they are placed behind the rollers 2a, 2b, 2c, etc. in set A, as shown in FIG. 2(a). Thereby, a gap S that is defined on the top between any two corresponding rollers of adjacent sets, in the direction from the rear end toward the front end of the roller support frame as viewed from the side can be smaller than a similar gap found in the prior art as shown in FIG. 9.
Then, when a particular article that is placed across the rollers in the adjacent sets A and B is moving forward along the rollers, passing over the gap S defined on the top between the two corresponding rollers in the direction from the rear end toward the front end of the roller support frame, the article can be moved while it is maintained at a constant height because the gap S is smaller and the article is supported by the outer top sides of any two adjacent rollers 2a, 2b, 2c, etc. in set A, and by the outer top sides of any two adjacent rollers 12a, 12b, 12c, etc. in set B that is adjacent to set A. As the article can be moved in this way, it will not be jolted or produce any vibrations or large noise.
Each of the rollers in one set, such as set A in this case, may be axially offset relative to a corresponding one of the rollers in the other set, such as set B, by a distance that is equal to one half to one fourth the interval between two adjacent rollers in set A or B. as measured from axis to axis.
The offset of each roller in one set relative to a corresponding roller in the other set may be adjusted, depending on the diameter of the roller or the dimension of the bottom of a particular article that extends across the rollers.
When the offset is set to a value that is equal to one half the axis-to-axis interval between the two adjacent rollers, for example, the article can be moved with stability and without causing any appreciable jolting motion or producing any large noise.
If the offset is set to any smaller value, such as one third, one fourth or much smaller, the article can be moved with less jolting motion and less noise. In any event, the offset value should be determined by considering manufacturing costs and ease of maintenance. In this respect, the offset should preferably be set to any value between one half and one fourth.
Referring now to FIG. 5, the roller support frame 1 is described in detail. The roller support frame 1 includes a lower bearing segment 3 and an upper bearing segment 4 that is mounted on the lower bearing segment 3.
More specifically, the lower bearing segment 3 has a flat surface on its upper side that supports each parallel set of rollers so that respective roller shafts can be maintained in the same plane. The upper bearing segment 4 has recesses for accepting the respective roller shafts, which are located on the lower side of the upper bearing segment 4 facing the upper side of the lower bearing segment 3 and are positioned to face the flat surface on the lower bearing segment 3.
Preferably, each recess on the upper bearing segment 4 should have a depth that is at least equal to the diameter of each roller shaft, and should have a bottom that is curved to conform to the outer peripheral surface of each roller shaft.
In this way, each of the roller shafts in each parallel set may be supported so that the roller shafts can be placed in the same plane. Thus, the rollers can have identical heights that meet the practical allowable precision requirements. As such, the articles can be moved without causing any jolting motion or vibrations.
As each roller shaft is supported by the flat surface of the lower bearing segment, the lower side (weight transmitting side) of each roller shaft can make contact with the flat surface of the lower bearing segment both linearly and circularly. This is substantially equivalent to linear contact, which may reduce rotational friction considerably. Therefore, the contact area may be reduced accordingly, which prevents dust from building up at the contact area.
As each roller shaft is supported by the flat surface of the lower bearing segment as described above, each recess that is provided on the lower side of the upper bearing segment for accepting the roller shafts may only serve as the positioning means for the rollers. Therefore, the recess needs not to accept the total periphery of the roller shaft. This permits the contact area between each roller shaft and the inner peripheral wall of the recess to be extremely small, which meets an object of the present invention. What is required in this case is that the recess has a depth that is equal to the diameter of each roller shaft and that the bottom of the recess is curved to conform to the outer peripheral surface of each roller shaft.
It should be understood that the present invention is not limited to any particular shape of the recess, and the recess may have the inner peripheral wall formed like a curve or angle.
One advantage of the present invention is that it permits goods or articles such as canned drinks or bottled drinks to be maintained at a constant height when they are moving along the rollers from the rear end toward the front end of the showcase assembly unit. Thus, the individual articles can be moved with stability and without causing any jolting motion or producing any large noise.
Another advantage of the present invention is that many rollers can be mounted in the same plane with high precision, and those rollers can rotate with less frictional force.